In an analog type crystal watch having a calendar display, the output of a motor comprising a stator, a driving coil, and a rotor is transmitted to a fifth wheel, a fourth wheel, a third wheel and a second wheel and is then transmitted to a cylindrical member, a cylindrical wheel, a second hand, a minute hand, an hour hand and a calendar mechanism. In the case of a wristwatch, the load on the stepping motor is extremely small except for the time during which the calendar is switched so that a torque of about 1.0 g-cm in the second wheel is sufficient. However, when the calendar is being switched, a torque several times higher than this is required. The time required for switching the calendar within a 24 hour period is at most only about 6 hours. However, in the mechanism according to the prior art there is the problem that sufficient electric power for operating the calendar driving mechanism in a stable manner must always be supplied from the power supply. This results in a large drain on the battery.
In an electronic watch according to the prior art, the circuitry for driving the stepping motor comprises an oscillator circuit generating a signal of, for example, 32,768 Hz. A frequency divider circuit converts this to a one second signal which is converted by a pulse width combining circuit to a signal pulse having a pulse width of 7.8 msec and a period of 2 seconds. This is dephased and applied through inverters to the motor driving coil. As a result, an inverted pulse which changes direction once each second is applied to the coil so that the rotor, which is magnetized with two poles, rotates in one direction. In this manner the drive pulse width of the present day electronic watch is set by the required maximum torque as its standard. This has prevented obtaining a low power consumption.